Sheet metal treating machine



Sept. 15, 1942. c. s. lwooLFoRD SHEET METAL TREATING MACHINE Filed Feb.28, 1940 3 Sheets-Sheet l Q2. RS N,

3 "Sheets-Sheet 2 Filed Feb. 28,11940 Sept. 15,1942. c s wooLFoRD SHEETMETAL TREATING MACHINEA Patented Sept. 15, 1942 SHEET METAL TREATINGMACHINE Custis S. Woolford, South Orange, N. J., assignor to AmericanCan Company, NewYork, N. Y., a corporation of New Jersey ApplicationFebruary 28, 1940, Serial No. 321,327

7 Claims.

'Ihe present invention relates to a machine for -treating metallic sheetmaterial, and has particular reference to'y preparing such material forcan manufacture or similar .purposes wherein sealed joints or seams areproduced and wherein the sheets are sprayed with a deoxidizing mediumpreparatory to sealing of theseams.

In can manufacture, sheets or strips of steel or iron, usually referredto as black plate, are coated with tin to produce the well knowncommercial tinplate so widely used in the manufacture of tin cans. Cansmade from tinplate are first blanked out and the blanks are formed intotubular shape. Edges of the blank are joined in a side seam to producethe tubular can body. Such a side seam may include an overlapping or aninterfolding of the blank edges and these edges may be soldered orwelded together to make a tight joint.

For some products the use of untinned black plate has been founddesirable for the manufacture of cans. However, it has been founddifficult to solder or weld the side seams of such cans because of theoxide surface of the black plate. The same is also true of some metalliccoated sheets other than those which are tin coated. Such oxide surfacesmay be prepared for soldering, etc., by deoxidization.

The instant invention contemplates a machine for overcoming thisdifficulty by preparing the blanks in a deoxidizing medium so that theside seam edges may be readily soldered or welded.

An object, therefore. of the` invention is. the provision of a blackiron'or other sheet metal treating machine wherein the iron sheets aresprayedwith a deoxidizing medium preparatory to being formed into cansand as an incident to having their edges sealed in a seam.

Another object is the provision of such a machine wherein the deoxidizedsheets are immediately sprayed with hot clean water to wash offthevdeoxidizing medium and are then thoroughly dried to prevent rusting.

Another object is the provision of a machine of this character whereinthe deoxidizing treatment may be localized or limited to certain deli- Ynite portions of the sheets so that needless or unnecessary treatment ofthe entire sheet may be eliminated.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, takenin connection with the accompany drawings, discloses a preferredembodiment thereof.

Referring to the drawings:

I ing chamber l5. The-.chambersare preferably` Figure i is a top planview of amachine embodying the instant invention, parts being brokenaway and partsshown in section;

Fig. 2 is a longitudinal vertical sectional view taken substantiallyalong the line 2--2 in Fig. 1;

Fig. 3 is a 'transverse vertical sectional view taken substantiallyalong the line, 3 3 in Fig. 1; and

Fig. 4 Ais a transverse vertical sectional view taken substantiallyalong the line 4-4 in Fig. 2.

As a preferred embodiment of the. invention the drawings disclose amachine in which metallic sheets A are subjected to adeoxidizingtreatment prior to being formed into containers and containerparts. In such a treatment' the sheets are first sprayed with a liquiddeoxidizing medium or agent such as for examplehot hydrochloric acid orhot sulphuric acid. f

After such an acid treatment the sheetsv are immediately washed off bybeing. sprayed with hot clean water. This washing `is Iollowedby-adrying treatment wherein hot air is blown against i the sheets. Thedrying action prevents the sheets thus treated from rusting.

The machine for subjecting the sheets A to such a deoxidlzing treatmentpreferably includes a casing Il having transverse partition Vwalls l2.

which divide the Y casing into three separate 1 chambers. These chambersincludes. deoxidizing chamber I3, a washingfhamber Il, and a dryclosedby acover platefyl which is bolted to the top of the casing-.j g

The sheets deoxidized are fed into the machinapreferably by hand and ina` horizontal positionf,"alons a feed table" which is secured to thefront end of themain casing Il. The sheets so fed enter the deoxidizing`chamber I3 near thetop and through an opening I8 providedin the casingjust underthev Cover plate f6.

Sheets A entering the deoxidizing chamber i3 are received withlnandbetween aipair oi.' verl tically disposed screw conveyors 2| veachhaving descending helical grooves 22 extending from top to bottom. Theseconveyors are spaced apart.l

one being adjacent each side-of the chamber, so that a sheet maybeinserted between them with its opposite edges disposed in thelrespective grooves 22. l

The conveyors 2| are mounted on verticalshafts vM. 'I'he ylower ends ofthe shafts are plate Il. `T'he shafts are continuously rotated stitutethe bottoms of thescrews.

in unison and in the proper direction by sprockets 21 which are carriedon their upper ends. The sprockets are preferably driven by endlesschains 23. There is one of these chains on each side of the machineextending longitudinally thereof.

As the conveyor screws 2| rotate, a sheet A supported in the helicalgrooves 22 of the screws, is carried down into the deoxidizing chamberI3. Vertical guide rails 3|, 32 disposed adjacent the unsupported edgesof the sheets confine them to a vertical path of travel. Rails 3| aresecured to the entrance end wall of the main casing II, while rails 32are secured at their upper ends to lugs 33 which depend from the coverplate I6.

As the body blank moves down into the deoxidizing chamber I3 its sideseam edges (the edges supported in the helical grooves 22) are sprayedwith the deoxidizing liquid hereinbefore mentioned. This spraying iseffected by means of a pair of vertical spray heads 35 which arelocated, one adjacent each corner of the moving blank as shown inFig. 1. Adjacent the blank the spray heads are formed with a verticalline of small spaced spray holes 36. Each spray head is formed on theinner end of a horizontal pipe 31 which extends through the side wallsof the main casing |I. Outside the casing the pipe connects with anysuitable source of supply of the deoxidizing medium.

Hence the deoxidizing liquid flowing through the main supply pipes 31,enters the spray heads 35 and is dischargedv from the holes 36 in a finespray. The holes are located in the spray heads so that the sprayissuing therefrom is directed longitudinally of the side seam edge ofthe blank since this is the only part of the blank which it is desiredto be deoxidized;` This spraying action is continuous along the entirelength of the spray head and hence as the blank moves down through thespray both sides of both marginal side seam edges are thoroughlysaturated with the deoxidizing acid. A drain pipe 33 is provided in thebottom of the chamber to drain off the residual or surplus acid andprevent its accumulation in the chamber.

Near the bottom of each of the conveyor screws 2| the helical groove 2 2changes to a greater pitch so that the lowermost1 blank of the pluralitymoving-down in the chamber, may be rapidly separated from the others fordischarge from the conveyor. When a blank reaches this portionkofftheconveyor it quickly descends into engagement with discharge discs 42which con- There is one disc for each screw and each disc is formed witha discharge nger 43. A

A blank upon reaching the upper surface of the discharge discs 42, ispositioned in front of the discharge ngers 43 rotating with the screws.These fingers engage the rear edge of the blank and sweep it forward(toward the right in Figs. 1 and 2) away from the screws.

longitudinally of the deoxidizing chamber I3.

One end of each support rail 44 is secured to one of the vertical guiderails 3|. The opposite end is secured to one of a similar pair ofvertical guide rails 46 which are secured to the first partltion wall I2in the main casing I. Permanent magnets 41, insulated from and securedto the support rails 44, tend to hold back on the moving blank, thusserving as a drag to prevent the During this advvancement the blankslides along the top of a t pair of horizontal support rails 44l whichextend blank from moving ahead too fast when it is ejected from thedeoxidizing conveyor screws.

A discharged blank A, moving along the support rails 44, comes to restagainst the vertical guide rails 46 and is then between two auxiliary 'ldeoxidizing screw conveyors 5I. These auxiliary conveyors are formedwith ascending helical grooves 52. Each screw conveyor is mounted on avertical shaft 53 journaled at its lower end in a bearing 54 which isformed in the main casing II, and at its upper end in a bearing 55formed inthe cover plate I6.

` The auxiliary conveyors 5| are rotated in time with the conveyors 2|by sprockets 56 which are carried on the upper ends of the shafts 63.These sprockets are driven by chains 51, there being one chain extendingalong each side of the machine. Adjacent the sprockets 56 there areVother sprockets 58 which are carried on the shafts 53. It is thesesprockets which drive the chains 26 and thereby rotate the maindeoxidizing screws 2|.

Hence when a transferred blank A comes into position between 'theauxiliary screw conveyors 5|, its side seam'edges enter the helicalgrooves 52. The rotation of the screws carries the blank up toward thetop of the chamber. During this vertical lift movement the sheet isguided by the vertical rails 46 and also by the rear edge of the guiderails 32 hereinbefore mentioned.

While thus moving upwardly the side seam edges of the blank are againsprayed with the deoxidizing acid. This is brought about by sprayissuing from a line of spray holes formed in the inner face of themiddle spray heads and also by a similar line of holes in a pair ofspray heads 6| (Fig. 1). 'These heads are vertically disposed adjacentthe guide rails 46 and are formed on the inner ends of main supply pipes62 which extend through the side walls of the main casing with thesupply ofdeoxidizing medium.

When a blank A reaches the tops of these auxiliary conveyor screws 5Iits side seam edges/are completely deoxidized and the blank is ready tobe discharged from the deoxidizing chamber I3 preparatory to enteringthe adjacent washing chamber I4. Here the upper-most sheet is separatedfrom the others in the same manner as in the main' conveyor screws 2|. Agroove of greater pitch and forming a continuance of the groove 62 isprovided for this purpose.

The discharge of the separated blank is effected by discharge fingers 65which are identical to the discharge fingers 43 on the main screwconveyors 2|. These ngers 65 are formed on discharge discs 66 on the topends of the auxiliary conveyor screws. 'I'he fingers, rotating with theVscrews, engage behind the blank as it comes adjacent the discharge discsand sweep the blank forward (toward the right in Figs. 1 and 2) andclear of the screws.

The deoxidized blank A thus discharged from the deoxidizing chamberslides along a pair of inverted support rails 66 which depend from thebottom of the cover plate I6. Permanentmagnets 69 insulated from andsecured to the support rails hold the blank against the rails whilemoving therealong.

'I'he detailed description of the machine thus far has been confined tothe deoxidizing unit of the machine. The blankwashing unit containingthe chamber I4 andthe blank drying unit with the chamber I6 are bothidentical in construction and operation, with one exception, to

The outer ends o'f these pipes are connected h the deoxidizing unit justexplained. The exception is that'in the washing unit, hot clean water issprayed from heads similar to the spray heads 35, 6I and in the dryingunit, hot air is preferably discharged from the spray heads to dry theblanks. In view of this similarity of parts .it is thought that only avery brief description of the l two` following units will suffice for aclear understanding of the machine.

In the washing chamber I4 there are two pairs of spaced verticallydisposed screw conveyors, a pair of entrance Vscrews 1I and a pair of`exit screws 12 arranged as in the deoxidizing chamber I3. The entrancescrews 1|'are formed with descending helical grooves 13 while the exitscrews 12 are formed with ascending helical grooves 14. 'I'he entrancescrews 1I are mounted on vertical shafts 1B which are journaled inbearings 11 formed in the bottom of the main casing and in bearings 18which are Journaled in the cover plate I6. The exit screws 12 aremounted on vertical shafts 19 (see also Fig. 3) which are journaled inbearings 8| of the main casing II and in bearings 82 of the cover plateI6. f

'Ihe shafts 16, 19 on each side of the machine are rotated in unisonbyendless chains 35 which takeover sprockets 86, 81 mounted on therespective shafts.. Sprockets 88 also on the shafts 16 operatethe chains51 of the auxiliary-screws 5I in the deoxidizing chamber I3. The shafts81 also carry bevel gears 9| which mesh with similar bevel gears 92carried on a main drive shaft 93 journaled in bearing brackets 94 formedon the cover plate IB. This is the main drive shaft of the entiremachine and may be rotated from any suitable source of power.- A pulley95 is provided for this purpose. i

When a deoxidized blank A is discharged from the deoxldizing chamber I3it is pushed directly into the helical grooves 13 of the entrance screws1I. into the washing chamber I4. During this downward movement of theblank, it is retained in its vertical line of travel by vertical guiderails 91, 98. Rails 91 are secured to the chamber partition wall I2while rails 98 are fastened at their upper ends to lugs 99 which dependfrom the cover plate I6. i

While the blank is being carried down into the washing chamber I4 itsside seam edges are washed thoroughly to free them of any of thedeoxidizing acid which may adhere to the blank. This'washing is effectedby sprays of hotclean water which issue from a line of small spacedholes formed in a .pair of water spray heads |I. 'I'hese spray heads arelocated cn-each side of the machine between the entrance screws 1I andthe exit screws 12 and adjacent the side seam edges of the moving blankso that a spray of water may be projected entirely across the blanklongitudinally of the seam edge. The spray heads are formed on the innerends of water supply pipes |02. These pipes extend through the sidewalls of the main casing I and lead from any'suitable source of hotclean water. A drain pipe |03 is provided in the bottom of the chambertodrain away the used water.

When a partially washed blank A reaches the bottom of the entrancescrews 1| it is separated from the other blanks in the conveyor and ispushed directly into the grooves 14 of the exit screws 12. 'Ihistransfer is brought about by transfer ngers |05 which are formed ondischarge discs |06 on the bottom of the screws.

While traveling from one set of screws to the The rotating screws carrythe blank downother blanks in the conveyorand is discharged pend fromthe top plate I6.

l deoxidizing chamber l chamber mounted on vertical of the spray heads.

other the moving blank is supported on horizontal support rails |08. Oneend of each rail is secured to the vertical guide rails 91. The y otherend is secured to a similar pair ofguide rails |09 which are fastened tothe second tion wall I2 of the main casing II. Permanent magnets IIIinsulated from andsecured to. the support rails keep the blank inengagement with the rails and serve as a drag to prevent uncontrolledmovement when the blank is ejected clear of the entrance screws 1|.

The blank received by the exit screws 121s immediately picked up byitsascending helical grooves 14 and is thereby elevated to the top ofthe screws. During this upward movement'the blank is guided by thevertical guide rails 98, |09. The side seam edges of the blank are againwashed oif as they, ascend through the water sprays vcf the sprayheads'sIOI. Thiswashing is done by sprays `which issue from a second setof holes which are formed in the other side This completes the washingof the blanks.

When a completely washed blank reaches the top of the exit screws 12 itis separated from the from the washing chamber I4 by dischargef'lngers-.H5 which are formed'on discs II 6 on the top of 'the screws(see also Fig. 3). The discharged blank slides along a pair of invertedsupport rails I I1 secured to lugs |I8 which de- Pennanent magnets II9insulated from and secured to' the rails hold the moving blankagainsttherails. 'I'he discharged and completely washed blank. thus passes fromthe 'washing chamber I4 and enters the adjacent drying chamber I5..

In the drying chamber I5 there are two pairs of spaced verticallydisposed screw conveyors consisting of a pair of entrance screws |25vand a pair of exit screws |26'arranged as inthe I3 or as in the washingI4. The entrance screws |25 are formed with descending helical grooves|21 while the exit screws |26 are formedwith ascending helical grooves|28; 'I'he entrance screws |25 vare shafts I3I which are journaled inbearings |32 formed in the bottom of the main casing II and in bearings|33 which are journaled in the cover plate I6. 'I'he exit screws aremounted on vertical shafts |35 which are journaled in bearings |36 ofthe main casing I| and in bearings |31 of the cover plate I 6.

YTheshafts I3I, |35 on each side of the machine are rotated in unison byendless chains |39 which take over sprockets |4`I, I42mounted on therespective shafts. These shafts are driven by the main shaft 93 throughendless chains '|43 which operate over sprockets. |44 carried on theexit screw shafts,19y in the washing chamber I4 and over sprockets |45which are ycarried on ltle elitrance screw shafts |3I in the dryingcham- When a washed blank A isdischarged' from the washing chamber I5 itis pushed directly into the helical grooves |21 of the drying-entrancescrews |25.` The rotating screws carry the blank down into the dryingrchamber I5. yDuring this downward travel of the blank it is retained ina vertical line of travel by vertical guide rails |41, |48. Rails |41are secured to the second partition wall I2 whilerails |40 are fastenedat their u'pper ends to lugs |49 which depend from the c'over plate I6.

, While the blank is being carried down into the parti'- drying chamber|5 its side seam edges are dried thoroughly of any of the washing waterwhich may adhereto the blank. `This drying is effected by sprays of hotair which issue from a line of` small spaced holes formed in a pair ofair spray heads |5| These spray heads are located on each side of themachine between the entrance screws |25 and the exit screws |26 andadjacent the side seam`edges of the moving blank so that' a spray of hotair may be projected entirely across the blank longitudinally of theseam edge. The spray heads are formed on the inner ends of air supplypipes |52. These pipes extend through the side walls of the main casingand lead from any suitable source of hot air.

When the partially dried blank A reaches the bottom of the entrancescrews |25, it is separated from the other blanks as hereinbeforedescribed. It then is pushed directly into the grooves |28 of the exitscrews |26. This transfer is done by way of transfer fingers |54 whichare formed on discharge discs |55 on the bottom of the screws.

While traveling from one set of screws to the other the moving blank issupported on horizontal support rails |51. One end of each of theserails is secured to the vertical guide rails |41. The other end iscarried on a similar pair of guide rails |58 which are secured to theend wall of the main casing Il. Permanent magnets |59 insulated from andsecured to the support rails keep the blank in engagement with the railsand serve as'a drag to prevent uncontrolled movement when the blank isejected clear of the entrance screws |25.

The blank received by the exit screws |26 is immediately picked up byits ascending helical grooves |28 and is thereby elevated to the top ofthe screws. During this upward movement the blank is guided by thevertical guide rails |48, |58. The side seam edges of.-the `blank areagain subjected to'the drying treatment as they ascend through thel airsprays oi' the spray heads |5|. This second drying is done by spraysof'hot aix which issue from a second set of holes formed in the oppositeside of the spray heads. This completes the drying of the blanks.

e When the completely dried blank reaches the top of the exit screws |26it is separated from the` other blanks in the conveyor and is dischargedfrom the drying chamber by discharge fingers |62 which are formed ondiscson the top of the screws. The discharged blank slides along a pairof inverted support rails- |63 secured to the top plate I6. Permanentmagnets |64 insulated from and secured to the rails hold the movingblank against the rails. The discharged and completely dry blank thuspasses from the drying chamber |5 and falls into an adjacent chute |65which is supported `on the end wall of the main casing The blanks aredelivered from this chute in any suitable or preferred manner to adesired place of deposit.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the form, construction andarrangement of the parts without departing from the spirit and scope ofthe invention or sacrificing all of its material advantages, the formhereinbefore described being merely a preferred embodiment thereof.

I claim: i. VIn a machine for deoxidizing metallic sheets to permitsoldering or welding of localizedpor- .disposed adjacent'a furthersucceeding pair of tial pairs of conveyors, means for transferring tionsthereof into tubular can bodies, the combination of a plurality ofvertically disposed conveyors arranged in spaced pairs respectively forengagement with opposite marginal portions of the sheets to move thesame successively in opposite vertical directions through the machine,means cooperating with said conveyors for progressively transferringsaid sheets from one pair of said conveyors to a succeeding adjacentpair at, the termination of a vertical movement of the sheets in onedirection to obtain a further vertical movement of the sheets in theopposite direction, and means disposed between said pairs of conveyorsadjacent opposite ends of the sheets for spraying localized oppositeedge portions only of the moving sheets to deoxidize such portions forthe purpose described.

2. In a machine for treating metallic sheets to permit soldering orwelding thereof, the combination of a plurality of vertically disposedconveyors arranged in spaced pairs respectively for engaging oppositemarginal portions of a said sheet to move the same alternately inopposite vertical directions through the machine, means for transferringsaid sheets from one pair of said conveyors to another at thetermination` of each vertical movement iny one direction, means disposedadjacent an initial pair of said conveyors for spraying localized edgeportions only of the moving sheet to deoxidize such portions, meansdisposed adjacent a succeeding pair of said conveyors foi` washing thesurplus deoxidizing medium from said edge portions thereof, and meanssaid conveyors for drying the sheet after the deoxidizing and washingoperations.v

` 3. In a machine for treating metallic sheets to permit soldering orwelding -together of localized portions thereof into tubular can bodies,the combination of a plurality of vertically disposed screw conveyorsarranged in-spaced pairs' respectively for engagement with oppositemarginal portionsA of the sheets tomove the same` alternately inopposite vertical directions lthrough the machine, means disposedbetweenV and cooperating `with. said pairs of conveyorsv forprogressively transferring said sheets from one pair of said conveyorsto another atvthe termination of a vertical movement of the sheets inone direction to obtain a furtherv vertical movement of the sheets inthe opposite direction, means disposed between initial pairs ofconveyors adjacent opposite ends of lthe sheets for spraying localized'opposite edge portions only of the ymoving sheets to deoxidize suchportions while the` sheets are movedin opposite vertical directions bysaid inithe deoxidized sheets from the second of said initial conveyorpairs to a' succeeding pair of conveyors, means disposed between thesecond of said initial conveyor pairs and said succeeding pair of saidconveyors for washing'the surplus deoxidizing medium from said edgeportions of the sheets while the latter are moved vertically I by saidsucceeding conveyor pair.

4. In a machine for treating metallic sheets` to permit soldering orvi'r'eldingv thereof into tubular can bodies, the combination of aplurality of vertically disposed screw conveyors arranged in spacedpairs respectively for engaging opposite marginal portions of said`sheets to move the same. alternately in opposite vertical directionsthrough the machine, independent means disposed between adjacent pairsof screw conveyors for transferring said sheets horizontally from onepair of said conveyors to another at the termination of each verticalmovement in one direction, means disposed between adjacent initial pairsof said conveyors for spraying localized edge portions only of themoving sheets while the latter are moved vertically in opposite direc-Vtions by said initial conveyor pairs to deoxidize suoli localized sheetportions, means disposed between the second of said initial pairs ofconveyors and a succeeding pair of conveyors for washing the surplusdeoxidizing medium from said edge portions thereof, and means disposedbetween said succeeding conveyor pair and a still further succeedingpair of said conveyors for drying the deoxidized and washed sheets, andmeans for discharging the sheets thus treated from the machine.

5. A machine for treating sheets of black iron plate and the like topermit soldering and welding thereof into tubular bodies, whichcomprises in combination: a plurality of vertically disposed rotatablescrew conveyors arranged in pairs for propelling sheets along apredetermined path of travel in horizontal position and in oppositevertical directions, means for transferring said sheets in a horizontaldirection from one pair of conveyors to another, means adjacent aninitial pair of said conveyors for depositing a deoxidizing medium ontopredetermined localized edge portions only of said sheets to removescale and rust therefrom, devices disposed adjacent a succeeding pair ofsaid conveyors for washing said deposited deoxidizing medium oi saidlocalized edge portions of the sheets, and instrumentalities disposedadjacent a still further succeeding pair of said conveyors for dryingsaid sheets to prevent rusting thereof after the deoxidizing and washingoperations.

6. A machine for treating sheets of black iron plate and the like topermit soldering and welding thereof, which comprises in combination: a

plurality of vertically disposed cooperating ro.

tatable screw conveyors arranged in successive pairs for conveyingsheets in horizontal position along a predetermined vertical path oftravel in opposite vertical directions, means associated with each pairof conveyors for transferring the sheets along a horizontal path of'travel from one pair into the next adjacent pair, vertical guide railsdisposed adjacent said screw conveyors for retaining said sheets inproper position, Ameans disposed between said pairs of screw conveyorsfor guiding the sheets during their transfer from one pair of saidconveyors to another, magnets disposed adjacent said guiding means formain'- taining the sheets in contact therewith during the transferringoperation, and deoxidizing,

washing and drying devices respectively disposed adjacent succeedingpairs of said conveyors for depositing a deoxidizing medium on localizededge portions only of said sheets and for washing the remainingdeoxidizingmedium off said localized portions after it has performed itsfunction and for drying the deoxidized and washed sheets, all of saiddeoxidizing, washing and drying operations taking place while the sheetsare being conveyed in opposite vertical directions between successivepairs of said vertically disposed cooperating screw conveyors.

7. In a machine for treating sheets of black iron plate and the like topermit soldering and welding thereof into tubular can bodies, thecombination of a pair of spaced and parallel vertically disposedrotatable screw conveyors each having a helical screw thread of uniformpitch for engaging sheets adjacent opposite edges and for moving thesheets while in horizontal position along a vertical path-of travel,said screw thread at one end thereof changing into aV steeper pitch tomore rapidly separate the outermost sheet from the remainder of thesheets engaged by said conveyors, a disc rotatable with each of saidconveyorsandlocated adjacent an end thereof and each having av rotatabletransfer nger for engaging against an end of the separated sheet and forshifting it out of engagement with said pair of conveyors whileVmaintaining said sheet in a horizontal plane, a

outermost sheet from the remaining sheets inthe conveyors, a discmounted on the end of each of said second mentioned pair of conveyorsand each having a rotatable finger fory engaging and discharging theseparated sheet to a suitable place of deposit, and means disposedbetween said pairs of screw conveyors adjacent opposite ends of saidsheets for spraying a deoxidizing Y medium upon localized edge portionsonly of both sides of said sheets at opposite ends of the latter fordeoxidizing and removing scale and rust from said localized edgeportions thereof while the sheets are engaged and moved in said oppositevertical directions by said adjacent pairs of screw conveyors.

C'USTIS S. WOOLFORD.

